Recently I wrote about the newly observed CBT bug in ESXi 6.x that, once again, could render your backups unusable. For the last two weeks only workarounds were available which could potentially lead to a extremely larger backup window and therefore making things not really better.

Veeam tested the patch against their backup product and it seemes that resetting CBT on all VMs is 100% mandatory to get the patch to work. So simply installing the patch is not enough, you HAVE TO reset CBT.